ing

options.go

@@ -1,7 +1,6 @@
 package overflow_grpc_pool
 
 import (
-	"log"
 	"time"
 
 	"google.golang.org/grpc"
@@ -10,6 +9,7 @@ import (
 const (
 	// DefaultWriteTimeout is default value of Write Timeout
 	DefaultIdleTimeout = 0
+	DefaultMaxCapacity = 1
 )
 
 type (
@@ -34,10 +34,12 @@ func (o *Options) Validate() *Options {
 		o.MaxIdle = 0
 	}
 	if o.MaxCapacity <= 0 {
-		log.Panicln("Max capacity of Pool must be greater than 0.")
+		o.MaxCapacity = DefaultMaxCapacity
 	}
 	if o.Creators == nil {
-		log.Panicln("Creators of Pool must be specified.")
+		o.Creators = func() (*grpc.ClientConn, interface{}, error) {
+			return nil, nil, nil
+		}
 	}
 
 	return o

pool.go

@@ -1,8 +1,8 @@
 package overflow_grpc_pool
 
 import (
+	"context"
 	"errors"
-	"log"
 	"time"
 
 	"google.golang.org/grpc"
@@ -29,14 +29,16 @@ type Pool interface {
 }
 
 type pool struct {
+	ctx         context.Context
 	options     *Options
 	instances   map[interface{}]*pooledInstance
 	instancesCh chan *pooledInstance
 }
 
-func New(o *Options) (Pool, error) {
+func New(ctx context.Context, o *Options) (Pool, error) {
 	var err error
 	p := &pool{
+		ctx:         ctx,
 		options:     o.Validate(),
 		instances:   make(map[interface{}]*pooledInstance, o.MaxCapacity),
 		instancesCh: make(chan *pooledInstance, o.MaxCapacity),
@@ -77,17 +79,19 @@ func (p *pool) createInstance() error {
 	return nil
 }
 
-func (p *pool) destroyInstance(i interface{}) {
+func (p *pool) destroyInstance(i interface{}) error {
 	var err error
 	pi, ok := p.instances[i]
 	if !ok {
-		return
+		return nil
 	}
 	err = pi.clientConn.Close()
 	if nil != err {
-		log.Printf("pool: ClientConn close error: %v", err)
+		return err
 	}
 	delete(p.instances, i)
+
+	return nil
 }
 
 func (p *pool) get() (*pooledInstance, error) {